Thoai Pham - Academia.edu (original) (raw)
Papers by Thoai Pham
Ophthalmologe, Sep 15, 1997
Journal of Refractive Surgery, 2003
To investigate intraoperative optical coherence pachymetry during laser in situ keratomileusis (L... more To investigate intraoperative optical coherence pachymetry during laser in situ keratomileusis (LASIK). In an initial clinical evaluation, three patients with myopia and myopic astigmatism were studied. Corneal thickness was assessed with optical pachymetry based on low-coherence interferometry during LASIK. The attempted mean spherical equivalent refraction was -5.70 +/- 2.00 D with a mean calculated stromal ablation depth of 95 +/- 18 microm. Intraoperative optical coherence pachymetry was reproducible in all patients during the different stages of LASIK, demonstrating a mean flap thickness of 141 +/- 30 microm with a residual corneal stroma of 274 +/- 24 microm at the end of the laser ablation. The immediate postoperative corneal thickness revealed marked swelling. This initial clinical evaluation proved that intraoperative optical coherence pachymetry may be an important safety feature for monitoring flap and residual stromal thickness during LASIK. It may be particularly helpful in the effort to avoid iatrogenic corneal ectasia in patients with thin corneas, higher refractive corrections, and LASIK enhancements.
Klinische Monatsblätter für Augenheilkunde, 2006
Klinische Monatsblätter für Augenheilkunde, 2005
Klinische Monatsblätter für Augenheilkunde, 2004
Klin Monatsbl Augenheilk, 2008
BACKGROUND Staining of the retinal surface has improved the intraoperative removal of semitranspa... more BACKGROUND Staining of the retinal surface has improved the intraoperative removal of semitransparent membranes during macular surgery. The purpose of this study was to evaluate the clinical experiences with brilliant blue G (BBG) staining of the retinal surface. METHODS BBG (Brilliant peel, Fluoron) was applied during vitrectomy and macular surgery in 43 patients. In 47 % there was a macular hole (MH), whereas 53 % had epiretinal membranes (ERM). Intraoperatively BBG was applied on the retinal surface under infusion or air conditions for 30 - 60 s. In MH the internal limiting membrane (ILM) and in ERM the membrane was removed. Postoperatively all patients were examined on average after 9 weeks. RESULTS Although intraoperative BBG staining was less intensive compared to ICG staining, the staining was sufficient to safely remove the semitransparent membranes in all cases. In all patients with MH hole closure was achieved, and in 96 % with ERM the metamorphopsiae decreased. The mean decimal visual acuity increased from 0.25 ± 0.13 to 0.37 ± 0.20 (p < 0.05) and improved in 63 % of the patients. Clinically, there were no toxic side-effects from BBG staining. CONCLUSIONS BBG allowed a complete and selective staining of the retinal surface. Thus, ILM and ERM could be removed safely during macular surgery. No clinical retinal toxicity was observed.
Klin Monatsbl Augenheilk, 2008
Klin Monatsbl Augenheilk, 1998
Klinische Monatsblätter für Augenheilkunde, 2010
Hintergrund: Die posteriore lamellare Keratoplastik (DSAEK) ist ein mittlerweile etabliertes Verf... more Hintergrund: Die posteriore lamellare Keratoplastik (DSAEK) ist ein mittlerweile etabliertes Verfahren zur Therapie von endothelialen Hornhauterkrankungen. Ziel war die Evaluation der Ergebnisse dieser Technik hinsichtlich der Funktion und Morphologie im Verlauf. Methoden: Bisher wurden insgesamt 52 Augen von 47 Patienten (69±10 Jahre) in der Klinik fur Augenheilkunde Neukolln mit einer DSAEK versorgt. Postoperativ wurden die visuellen und refraktiven Ergebnisse, der Endothelzellverlust, sowie die Transplantat- und Gesamthornhautdicke bei allen durchgefuhrten Eingriffen ausgewertet. Ergebnisse: Es zeigte sich nach einem durchschnittlichen Nachbeobachtungszeitraum von 38±28 Monaten ein Visusanstieg von 0,18±0,1 auf 0,56±0,3. Dabei fand sich ein Endothelzellverlust von im Mittel 44±18%. Die mittlere Transplantatdicke betrug zentral 154±73µm, die Gesamthornhaut 678±80µm. In 11 Fallen war ein Re-Bubbling erforderlich, in insgesamt 7 Fallen kam es zu einem primaren Tx-Versagen. Vereinzelt fanden sich eine milde Dezentrierung, Interfacedebridement, Urrets-Zavalia-Syndrom oder Synechienbildung, die nach chirurgischen Optimierungen nicht mehr zu beobachten waren. Eine Abstossungsreaktion konnte in keinem Fall nachgewiesen werden. Schlussfolgerung: Die hintere lamellare Keratoplastik (DSAEK) ist ein etabliertes und geeignetes Verfahren zur Behandlung von endothelialen Hornhauterkrankungen. Bei weiterer technischer Entwicklung und optimaler Nachsorge sind zukunftig noch bessere Ergebnisse zu erwarten.
Klinische Monatsblätter für Augenheilkunde, 2006
Background: Covered sclerotomy was developed as a minimally invasive modification of filtering gl... more Background: Covered sclerotomy was developed as a minimally invasive modification of filtering glaucoma surgery. In this prospective study the clinical results are compared after one year. Patients and Methods: 58 eyes with advanced glaucoma were studied. 32 eyes had a covered sclerotomy (ST) and 26 had an ST with viscoelastic filling of the anterior chamber in order to reduce the postoperative hypotony rate (ST+H). The ST procedure consisted in the preparation of a 4-mm corneoscleral tunnel incision with a T-shaped 1.75-mm wide perforation and radial transection of the tunnel floor. Results: The preoperative intraocular pressure (IOP) was on average 30±8.5mmHg (ST) and 26±8.3mmHg (ST+H). After 1 year the IOP decreased significantly (P <0.05) to 17 ± 3.7 mmHg (ST) and 17 ± 2.9 mmHg (ST+H). The mean TOP reduction was 37% (ST) and 30% (ST+H). Revisions were required in 37% (ST) and 15% (ST+H) of the cases. The postoperative hypotony rate was 34 % in both groups. The number of morphologically functional filtering blebs was 60% (ST) and 70% (ST+H) after one year. Conclusions: The covered sclerotomy required minimal surgical manipulations of the conjunctiva and sclera. After 1 year a significant reduction of the IOP was achieved. However, the occurrence of bleb scarring could not be lowered compared to trabeculectomy. Therefore further modifications with the primary application of antimetabolites are planned.
Klinische Monatsblätter für Augenheilkunde, 2009
Journal of Cataract and Refractive Surgery, 2004
Purpose: To assess the continuous intraoperative monitoring of central corneal thickness (CCT) ch... more Purpose: To assess the continuous intraoperative monitoring of central corneal thickness (CCT) changes during laser in situ keratomileusis (LASIK) using online optical coherence pachymetry (OCP).
Journal of Cataract & Refractive Surgery, 1997
To evaluate the effect of incision location or clinically relevant preoperative oblique astigmati... more To evaluate the effect of incision location or clinically relevant preoperative oblique astigmatism. Department of Ophthalmology, Virchow Medical Center, Humboldt-University, Berlin, Germany. This prospective study included 68 patients who had phacoemulsification and posterior chamber lens implantation using a standardized 7.0 mm self-sealing trapezoidal scleral tunnel incision. Each patient was randomly assigned to one of three incision locations: Group A, conventional superior incision; Group B, temporal incision; Group C, oblique incision centered on the steeper meridian (modified BENT incision). Astigmatism analysis was performed by manual keratometry and corneal topography. A significant mean reduction in astigmatism of 0.58 diopter (D) (P &amp;lt; .01) was achieved in only the modified BENT incision group. Postoperatively, significant flattening of 0.27 D (P &amp;lt; .01) in the steeper meridian as well as steepening of 0.29 D (P &amp;lt; .01) in the flatter meridian occurred. No decrease in astigmatism was noted in the superior or temporal incision groups. Five months postoperatively, vector analysis showed that surgically induced astigmatism was significantly higher in the superior incision group (1.16 D +/- 0.44 [SD]) than in the temporal incision group (0.66 +/- 0.32 D) or modified BENT incision group (0.82 +/- 0.50 D). Corneal topographic analysis confirmed these results within +/- 0.3 D. Only the oblique incision centered on the steeper meridian (modified BENT incision) effectively and predictably reduced preoperative oblique astigmatism. In eyes with clinically relevant oblique astigmatism, we recommend using a modified BENT incision.
Der Ophthalmologe, 2008
Microincision cataract surgery (MICS) is an important advancement in the field of cataract surger... more Microincision cataract surgery (MICS) is an important advancement in the field of cataract surgery. This article compares an aberration corrected hydrophilic acrylic intraocular lens (IOL) having a hydrophobic surface for MICS with a one-piece hydrophobic acrylic IOL with respect to capsule sac stability, image quality, and after-cataract formation over the course of 1 year. The operations were performed as bimanual MICS or coaxial phacoemulsification. Overall the results after implantation of the IOL by MICS can be regarded as positive in comparison to the standard operation.
12. Kongreß der Deutschsprachigen Gesellschaft für Intraokularlinsen-Implantation und refraktive Chirurgie, 1999
Problemstellung In jungster Zeit wird in amerikanischen Publikationen die Anwendung von intraokul... more Problemstellung In jungster Zeit wird in amerikanischen Publikationen die Anwendung von intraokularem Lidocain zur Lokalanasthesie wahrend Kataraktoperationen propagiert (Gills et al. , Koch et al. , J Cataract Refract Surg, Mai 1997). Obwohl uber keine Nebenwirkungen berichtet wird, liegen kontrollierte Studien v. a. uber eine mogliche Endotheltoxizitat des Anasthetikums nicht vor.
Klinische Monatsblätter für Augenheilkunde, 2014
Absence of capsular support or extended zonulolysis is today the main indication for retroiridal ... more Absence of capsular support or extended zonulolysis is today the main indication for retroiridal enclavation of the unfoldable PMMA iris claw lens (Verisyse®/Artisan®) if there is sufficient iris support. Contraindications are uveitis or ischaemic retinopathies. 'In-the-bag' IOL dislocation due to PEX zonulopathy usually occurring 8 years after phacoemulsification is the main indication. For complicated phacoemulsification with extended zonular defect the retroiridal iris claw lens (Verisyse®/Artisan®) has become the stand-by IOL of first choice. A rare indication for Verisyse is optical rehabilitation after lens luxation into the vitreous in combination with vitrectomy. 81 eyes were analysed. With laseroptic biometry target refraction was within 1 D for 100 % of the 'in-the-bag' luxation cases and in 62 % for the other more complicated cases. Wavefront analysis showed no significant difference for optical quality between retroiridal iris claw lens and a endocapsular...
Klinische Monatsblätter für Augenheilkunde, 2004
Approximately 14 % of cataract surgery patients receive blood-thinning agents. In a prospective s... more Approximately 14 % of cataract surgery patients receive blood-thinning agents. In a prospective study, the influence of oral anticoagulants on intraoperative and postoperative hemorrhages in patients undergoing cataract surgery in topical anesthesia was investigated. 128 patients presenting for cataract surgery under oral anticoagulation were included. The mean preoperative prothrombin time was 39 +/- 18 %. Most patients (81 %) continued their oral anticoagulation (prothrombin time 34 +/- 13 %). All surgeries were performed in topical anesthesia. In 9 patients (7 %) an ocular hemorrhagic event was observed. These were not sight-threatening and resorbed spontaneously within a few days. Only one patient (0.8 %) had a slight hemorrhage in the anterior chamber. There were no differences (P > 0.05) between patients with or without hemorrhagic complications in the postoperative visual acuity, the intraocular pressure, the prothrombin time or the discontinuation of oral anticoagulants. ...
12. Kongreß der Deutschsprachigen Gesellschaft für Intraokularlinsen-Implantation und refraktive Chirurgie, 1999
Hintergrund Neben der Peribulbaranasthesie als Standardverfahren der Lokalanasthesie bei Katarakt... more Hintergrund Neben der Peribulbaranasthesie als Standardverfahren der Lokalanasthesie bei Kataraktoperationen gibt es in letzter Zeit zunehmend Berichte uber Verfahren, bei denen auf einen Einstich in die Haut oder die Konjunktiva vollig verzichtet werden kann. Hierzu zahlt auch die direkte intraokulare Injektion von konservierungsstofffreien Lokalanasthetika.
Ophthalmologe, Sep 15, 1997
Journal of Refractive Surgery, 2003
To investigate intraoperative optical coherence pachymetry during laser in situ keratomileusis (L... more To investigate intraoperative optical coherence pachymetry during laser in situ keratomileusis (LASIK). In an initial clinical evaluation, three patients with myopia and myopic astigmatism were studied. Corneal thickness was assessed with optical pachymetry based on low-coherence interferometry during LASIK. The attempted mean spherical equivalent refraction was -5.70 +/- 2.00 D with a mean calculated stromal ablation depth of 95 +/- 18 microm. Intraoperative optical coherence pachymetry was reproducible in all patients during the different stages of LASIK, demonstrating a mean flap thickness of 141 +/- 30 microm with a residual corneal stroma of 274 +/- 24 microm at the end of the laser ablation. The immediate postoperative corneal thickness revealed marked swelling. This initial clinical evaluation proved that intraoperative optical coherence pachymetry may be an important safety feature for monitoring flap and residual stromal thickness during LASIK. It may be particularly helpful in the effort to avoid iatrogenic corneal ectasia in patients with thin corneas, higher refractive corrections, and LASIK enhancements.
Klinische Monatsblätter für Augenheilkunde, 2006
Klinische Monatsblätter für Augenheilkunde, 2005
Klinische Monatsblätter für Augenheilkunde, 2004
Klin Monatsbl Augenheilk, 2008
BACKGROUND Staining of the retinal surface has improved the intraoperative removal of semitranspa... more BACKGROUND Staining of the retinal surface has improved the intraoperative removal of semitransparent membranes during macular surgery. The purpose of this study was to evaluate the clinical experiences with brilliant blue G (BBG) staining of the retinal surface. METHODS BBG (Brilliant peel, Fluoron) was applied during vitrectomy and macular surgery in 43 patients. In 47 % there was a macular hole (MH), whereas 53 % had epiretinal membranes (ERM). Intraoperatively BBG was applied on the retinal surface under infusion or air conditions for 30 - 60 s. In MH the internal limiting membrane (ILM) and in ERM the membrane was removed. Postoperatively all patients were examined on average after 9 weeks. RESULTS Although intraoperative BBG staining was less intensive compared to ICG staining, the staining was sufficient to safely remove the semitransparent membranes in all cases. In all patients with MH hole closure was achieved, and in 96 % with ERM the metamorphopsiae decreased. The mean decimal visual acuity increased from 0.25 ± 0.13 to 0.37 ± 0.20 (p < 0.05) and improved in 63 % of the patients. Clinically, there were no toxic side-effects from BBG staining. CONCLUSIONS BBG allowed a complete and selective staining of the retinal surface. Thus, ILM and ERM could be removed safely during macular surgery. No clinical retinal toxicity was observed.
Klin Monatsbl Augenheilk, 2008
Klin Monatsbl Augenheilk, 1998
Klinische Monatsblätter für Augenheilkunde, 2010
Hintergrund: Die posteriore lamellare Keratoplastik (DSAEK) ist ein mittlerweile etabliertes Verf... more Hintergrund: Die posteriore lamellare Keratoplastik (DSAEK) ist ein mittlerweile etabliertes Verfahren zur Therapie von endothelialen Hornhauterkrankungen. Ziel war die Evaluation der Ergebnisse dieser Technik hinsichtlich der Funktion und Morphologie im Verlauf. Methoden: Bisher wurden insgesamt 52 Augen von 47 Patienten (69±10 Jahre) in der Klinik fur Augenheilkunde Neukolln mit einer DSAEK versorgt. Postoperativ wurden die visuellen und refraktiven Ergebnisse, der Endothelzellverlust, sowie die Transplantat- und Gesamthornhautdicke bei allen durchgefuhrten Eingriffen ausgewertet. Ergebnisse: Es zeigte sich nach einem durchschnittlichen Nachbeobachtungszeitraum von 38±28 Monaten ein Visusanstieg von 0,18±0,1 auf 0,56±0,3. Dabei fand sich ein Endothelzellverlust von im Mittel 44±18%. Die mittlere Transplantatdicke betrug zentral 154±73µm, die Gesamthornhaut 678±80µm. In 11 Fallen war ein Re-Bubbling erforderlich, in insgesamt 7 Fallen kam es zu einem primaren Tx-Versagen. Vereinzelt fanden sich eine milde Dezentrierung, Interfacedebridement, Urrets-Zavalia-Syndrom oder Synechienbildung, die nach chirurgischen Optimierungen nicht mehr zu beobachten waren. Eine Abstossungsreaktion konnte in keinem Fall nachgewiesen werden. Schlussfolgerung: Die hintere lamellare Keratoplastik (DSAEK) ist ein etabliertes und geeignetes Verfahren zur Behandlung von endothelialen Hornhauterkrankungen. Bei weiterer technischer Entwicklung und optimaler Nachsorge sind zukunftig noch bessere Ergebnisse zu erwarten.
Klinische Monatsblätter für Augenheilkunde, 2006
Background: Covered sclerotomy was developed as a minimally invasive modification of filtering gl... more Background: Covered sclerotomy was developed as a minimally invasive modification of filtering glaucoma surgery. In this prospective study the clinical results are compared after one year. Patients and Methods: 58 eyes with advanced glaucoma were studied. 32 eyes had a covered sclerotomy (ST) and 26 had an ST with viscoelastic filling of the anterior chamber in order to reduce the postoperative hypotony rate (ST+H). The ST procedure consisted in the preparation of a 4-mm corneoscleral tunnel incision with a T-shaped 1.75-mm wide perforation and radial transection of the tunnel floor. Results: The preoperative intraocular pressure (IOP) was on average 30±8.5mmHg (ST) and 26±8.3mmHg (ST+H). After 1 year the IOP decreased significantly (P <0.05) to 17 ± 3.7 mmHg (ST) and 17 ± 2.9 mmHg (ST+H). The mean TOP reduction was 37% (ST) and 30% (ST+H). Revisions were required in 37% (ST) and 15% (ST+H) of the cases. The postoperative hypotony rate was 34 % in both groups. The number of morphologically functional filtering blebs was 60% (ST) and 70% (ST+H) after one year. Conclusions: The covered sclerotomy required minimal surgical manipulations of the conjunctiva and sclera. After 1 year a significant reduction of the IOP was achieved. However, the occurrence of bleb scarring could not be lowered compared to trabeculectomy. Therefore further modifications with the primary application of antimetabolites are planned.
Klinische Monatsblätter für Augenheilkunde, 2009
Journal of Cataract and Refractive Surgery, 2004
Purpose: To assess the continuous intraoperative monitoring of central corneal thickness (CCT) ch... more Purpose: To assess the continuous intraoperative monitoring of central corneal thickness (CCT) changes during laser in situ keratomileusis (LASIK) using online optical coherence pachymetry (OCP).
Journal of Cataract & Refractive Surgery, 1997
To evaluate the effect of incision location or clinically relevant preoperative oblique astigmati... more To evaluate the effect of incision location or clinically relevant preoperative oblique astigmatism. Department of Ophthalmology, Virchow Medical Center, Humboldt-University, Berlin, Germany. This prospective study included 68 patients who had phacoemulsification and posterior chamber lens implantation using a standardized 7.0 mm self-sealing trapezoidal scleral tunnel incision. Each patient was randomly assigned to one of three incision locations: Group A, conventional superior incision; Group B, temporal incision; Group C, oblique incision centered on the steeper meridian (modified BENT incision). Astigmatism analysis was performed by manual keratometry and corneal topography. A significant mean reduction in astigmatism of 0.58 diopter (D) (P &amp;lt; .01) was achieved in only the modified BENT incision group. Postoperatively, significant flattening of 0.27 D (P &amp;lt; .01) in the steeper meridian as well as steepening of 0.29 D (P &amp;lt; .01) in the flatter meridian occurred. No decrease in astigmatism was noted in the superior or temporal incision groups. Five months postoperatively, vector analysis showed that surgically induced astigmatism was significantly higher in the superior incision group (1.16 D +/- 0.44 [SD]) than in the temporal incision group (0.66 +/- 0.32 D) or modified BENT incision group (0.82 +/- 0.50 D). Corneal topographic analysis confirmed these results within +/- 0.3 D. Only the oblique incision centered on the steeper meridian (modified BENT incision) effectively and predictably reduced preoperative oblique astigmatism. In eyes with clinically relevant oblique astigmatism, we recommend using a modified BENT incision.
Der Ophthalmologe, 2008
Microincision cataract surgery (MICS) is an important advancement in the field of cataract surger... more Microincision cataract surgery (MICS) is an important advancement in the field of cataract surgery. This article compares an aberration corrected hydrophilic acrylic intraocular lens (IOL) having a hydrophobic surface for MICS with a one-piece hydrophobic acrylic IOL with respect to capsule sac stability, image quality, and after-cataract formation over the course of 1 year. The operations were performed as bimanual MICS or coaxial phacoemulsification. Overall the results after implantation of the IOL by MICS can be regarded as positive in comparison to the standard operation.
12. Kongreß der Deutschsprachigen Gesellschaft für Intraokularlinsen-Implantation und refraktive Chirurgie, 1999
Problemstellung In jungster Zeit wird in amerikanischen Publikationen die Anwendung von intraokul... more Problemstellung In jungster Zeit wird in amerikanischen Publikationen die Anwendung von intraokularem Lidocain zur Lokalanasthesie wahrend Kataraktoperationen propagiert (Gills et al. , Koch et al. , J Cataract Refract Surg, Mai 1997). Obwohl uber keine Nebenwirkungen berichtet wird, liegen kontrollierte Studien v. a. uber eine mogliche Endotheltoxizitat des Anasthetikums nicht vor.
Klinische Monatsblätter für Augenheilkunde, 2014
Absence of capsular support or extended zonulolysis is today the main indication for retroiridal ... more Absence of capsular support or extended zonulolysis is today the main indication for retroiridal enclavation of the unfoldable PMMA iris claw lens (Verisyse®/Artisan®) if there is sufficient iris support. Contraindications are uveitis or ischaemic retinopathies. 'In-the-bag' IOL dislocation due to PEX zonulopathy usually occurring 8 years after phacoemulsification is the main indication. For complicated phacoemulsification with extended zonular defect the retroiridal iris claw lens (Verisyse®/Artisan®) has become the stand-by IOL of first choice. A rare indication for Verisyse is optical rehabilitation after lens luxation into the vitreous in combination with vitrectomy. 81 eyes were analysed. With laseroptic biometry target refraction was within 1 D for 100 % of the 'in-the-bag' luxation cases and in 62 % for the other more complicated cases. Wavefront analysis showed no significant difference for optical quality between retroiridal iris claw lens and a endocapsular...
Klinische Monatsblätter für Augenheilkunde, 2004
Approximately 14 % of cataract surgery patients receive blood-thinning agents. In a prospective s... more Approximately 14 % of cataract surgery patients receive blood-thinning agents. In a prospective study, the influence of oral anticoagulants on intraoperative and postoperative hemorrhages in patients undergoing cataract surgery in topical anesthesia was investigated. 128 patients presenting for cataract surgery under oral anticoagulation were included. The mean preoperative prothrombin time was 39 +/- 18 %. Most patients (81 %) continued their oral anticoagulation (prothrombin time 34 +/- 13 %). All surgeries were performed in topical anesthesia. In 9 patients (7 %) an ocular hemorrhagic event was observed. These were not sight-threatening and resorbed spontaneously within a few days. Only one patient (0.8 %) had a slight hemorrhage in the anterior chamber. There were no differences (P > 0.05) between patients with or without hemorrhagic complications in the postoperative visual acuity, the intraocular pressure, the prothrombin time or the discontinuation of oral anticoagulants. ...
12. Kongreß der Deutschsprachigen Gesellschaft für Intraokularlinsen-Implantation und refraktive Chirurgie, 1999
Hintergrund Neben der Peribulbaranasthesie als Standardverfahren der Lokalanasthesie bei Katarakt... more Hintergrund Neben der Peribulbaranasthesie als Standardverfahren der Lokalanasthesie bei Kataraktoperationen gibt es in letzter Zeit zunehmend Berichte uber Verfahren, bei denen auf einen Einstich in die Haut oder die Konjunktiva vollig verzichtet werden kann. Hierzu zahlt auch die direkte intraokulare Injektion von konservierungsstofffreien Lokalanasthetika.